Film viewer and reproducer



Aid

April 11, 1961 Filed June 19, 1958 H. G. REUTER, JR

FILM VIEWER AND REPRODUCER 3 Sheets-Sheet 1 III! r III INVENTOR.

HENRY E. REUTERJR.

BY Z

April 11, 1961 H. G. REUTER, JR 2,979,026

FILM VIEWER AND REPRODUCER Filed June 19, 1958 3 Sheets-Shee't 2 IN VEN TOR. HENRY E. REUIERJR.

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FILM VIEWER AND REPRODUCER United States Patent FILM VIEWER AND REPRODUCER Henry G. Reuter, Jr., Merchantville, N.J., assignor to Radio Corporation of America, a corporation of Delaware Filed June 19, 1958, Ser. No. 743,145

6 Claims. (Cl. 118-637) This invention relates to film viewers and reproducers generally, and more particularly to apparatus for viewing microfilm and for making an enlarged print of the microfilm by an electrophotographic process.

It is an object of the present invention to provide imroved apparatus for viewing enlarged images of microfilm and for reproducing these enlarged images by means 2,979,026 Patented Apr. 11, 1961 the arrows showing a portion of the developing mechaor" a direct electrophotographic process in a relatively short time.

Another object of the present invention is to provide improved apparatus for developing an electrostatic latent image on a sheet of photoconductivematerial in a mannerwhereby the sheet is caused to move along a predetermined path, and wherein the difierent steps in the electrophotographic process are initiated by. switches in response to the movement of the sheet.

A further object of the present invention is to provide novel developing apparatus which can be changed from an inoperative condition to an operative condition as, for example, upon the approach of a sheet to be developed to a developing zone.

In accordance with the present invention, the foregoing objects and related advantages are attained in improved apparatus comprising an operator section, a viewer section, and a base section. The operator section houses the optical elements, the film-holding apparatus and the operator controls for normal operation. The viewer section houses the viewing screen and the mirrors required for the projection of the enlarged image of the film. The base section houses the transport mechanism for the sheet to be developed and the apparatus for the electrophotographic process.

One feature of the present invention is the novel apparatus for applying a toner, developer powder, to the latent charge image on a sheet by means of a magnetic held. The magnetic field is utilized in a manner whereby the toner is attracted to the sheet only during the time the paper passes over a tray containing the toner intermixed with magnetic particles.

Another feature of the invention is the novel arrangement of apparatus whereby the steps in the electrophotographic process are carried out in response to switches that are actuated by the movement of a sheet of photo- Fig. 2 is a cross-sectional view taken along theplane 2-2 in Fig. 1, and viewed in the. directionfindicated by position.

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Fig. 3 is a fragmentary view, in side elevation, of an alternative solenoid mechanism for actuating a magnetic field producing mechanism;

Fig. 4 is a cross-sectional view of the developing mechanism taken along the plane 4-4 of Fig. 2, and viewed in a direction indicated by the arrows; and I Fig. 5 is a schematic diagram of the electrical system of the viewer and reproducer apparatus.

Referring now to Fig. 1 there is shown the film viewer and reproducer apparatus 10 comprising an operator section 12, a viewer section 14, and a base section 16. The operator section comprises a focusing knob 18 for adjusting a lens system 20, illustrated herein as a single lens. A film 21 to be viewed may be inserted between film guides 22in the direct path of a beam of light from a lamp 24 and through an optical condenser 26.

The operator section 12 also comprises a control panel 28 as a part of the general housing 30 of the apparatus 10. The housing 30 is provided with a slot 32 adjacent to the film guides 22 for inserting the film 21 therethrough for viewing purposes.

An enlarged image of the film 21 may be viewed on a frosted glass screen 34 by first projecting the image onto a fixed mirror 36, and then reflecting the image from the mirror 36 onto the screen 34. A movable mirror 38 is in a raised position indicated by the dashed lines 38a when the film 21 is being viewed. A cam 42, near the pivoted end of the mirror 38 actuates a limit switch 44 when the mirror 38 is in a down position, and actuates alimit switch 46 when it is in an up position. The movable mirror 38 is actuated by a motor 48a in response to a viewing switch 50 (Fig. 5) to raise the mirror 38, and by a motor 48b in response to a print switch '52 (Fig. 5) to lower the mirror 38, as shown in Fig. 5.

A shade 56, actuated by a motor 58a, is raised in response to the closing of the viewing switch 50. The upper position of the shade 56 is determined by an upper limit switch 60. The shade 56 is lowered by a motor 58b to a position determined by a lower limit switch 62 when the print switch 52 (Fig. 5) is actuated. It will now be understood that to print the image viewed on screen 34 the print switch 52 is actuated so as to lower the mirror 38 and to shut out any light that may come through the screen 34.

With the movable mirror 38 in its down position, as shown in Fig. 1, the image of the film 21 to be printed may be projected onto the fixed mirror 36, reflected there'- from to the mirror 38, and further reflected onto an endless belt 64 which will hold a sheet having a latent charge image thereon, as will be hereinafter explained. The movable mirror 38 is so positioned that when the film 21 is in focus on the screen 34, with the movable mirror 38 in the up position, the image projected onto the belt 64 will be in focus with the movable mirror 38 in the down" With this arrangement it is possible to focus the image of the film 21 onto the screen 34 for viewing with visible light, and to focus the image projected on the belt 64 with an ultraviolet component ofthe lamp 24 so that printing may take place with the ultraviolet component, if so desired. 1

A sheet 68 on which to reproduce the enlarged image of the film 21 may be cut from a roll 66 of special sheet material, such as paper having a photoconducti ve layer thereon. The sheet 68 is passed between input guide members 70 and between feed rollers 72 and 74. The roller 74 is driven by a motor 76 through a suitable clutch 78, 'as shown in Fig. 1. The clutch 78 is actuated by a solenoid 80. The sheet 68 passes through a shear mechanism 84 that may be actuated: by a solenoid 8 6. The

sheet 68 then is passed between a pair of oppositely disposed charging devices 88 for charging the sheet 68 with a uniform electrostatic charge by a corona discharge, in amanner well known in theart. The path of the sheet 68 will now be between the belt 64 and a belt 90. The belt 90 is looped around pulleys 92, 94, and 96 in a manner whereby the lower portion of the belt 92 is in contact with the belt 64.

The pulley 96 may be geared (not shown), or otherwise mechanically coupled, to a pulley 98 which, in turn, is driven by the motor 76. The belt 64 rides on an exposure platen 100 that is very slightly convex in shape so as to force the upper portion of the belt 64 against the lower portion of the belt 90 and to clamp the sheet 68 therebetween. The belt 64 is supported by pulleys 102, 104, and 18 6, in addition to the pulley 98.

A lower, slightly convex, platen 108 is disposed between the pulleys 102 and 104 in a manner to put pressure against the belt 64 and a belt 110. The belt 110 is supported by four pulleys 112, 114, 116, and 118 in a manner whereby the upper portion of'the belt 110 is pressed against the lower portion of the belt 64. It will now be understood that a sheet 68 can be made to move in a predetermined path between the belt 64 and the belt 90, through rear guides 120 and 122, and between the belt 64 and the belt 110. The sheet 68 may be ejected onto an exit plate 124, as indicated by the arrows 126 after it has been developed in a manner hereinafter to be explained.

'It will be understood that the belt 64 may be as Wide as the sheet 68. The belt 64may actually comprise a series of narrow belts ina side by side arrangement. On the other hand, the belts 98 and 110 are relatively narrow and function to grip the sheet 68 along its edge. Another setof belts (not shown) similar to the belts 90 and 110 are disposed along the opposite edge of the sheet 68 to transport it along its predetermined path.

The uniformly charged sheet 68 will go through all of the steps in the electrophotographic process during its travel along its predetermined path. When the leading edge of the sheet 68 hits the limit switch 82 the clutch 78 will be disengaged and the solenoid 86 will be actuated so that the-shear 84 will cut a single sheet 68 of paper from the roll 66. The sheet 68 will advance until its leading edge hits a switch 128. This switch 128 Will stop the motor 76, engaged to the pulley 98, so that the sheet 68 will become stationary. The switch 128 will also start a timer 129 (Fig. that has been previously preset, as by a timer control knob 130 on the control :panel 28, in a manner hereinafter to be explained. After the timer 129 has exposed the sheet 68 for a preset time, the motor 76 is started again, and the sheet 68 moves over a developer tray 132; The developer tray 132 contains a mixture 134 of finely divided iron filings and a pigmented developer powder, hereinafter called toner.

A toothed roller 136 within the tray 132 is pivoted for rotation by a motor 138, as shown in Fig. 2. It will now be understood that if the roller 136 is rotated it will pick up the mixture 134 between its teeth and move this mixture adjacent to the sheet 68, when the latter is between the belts 64 and 110. A pair of conveyor type screws 140 and 142, as shown in Fig. 4, are coupled to the roller 136 in a manner whereby the screws rotate in opposite directions within the mixture 134 for the purpose of spreading the mixture 134 evenly. This action also tends to keep the ratio of toner to iron filings uniform.

.Means are provided to-pull the mixture 134 up "against theexposed' surface of the sheet-68wherebythe pigmented developer powder of the mixture 134 will adhere to the exposed surface for printing an image thereon. To this end, :magnetic field means are provided. As'shown in Figs. -1 and 2, the magnetic field means may comprise a' The frame 146 includes a lower bar 147 of magnetic material to form a pole piece for the magnets 144. A rotary solenoid 150 may be actuated by switches 152 and 154, connected in series with each other, to rotate the normally horizontally disposed magnets to a vertical position, in response to the actuation of the switches 152 and 154 by the leading edge of the moving sheet 68. This action brings a magnetic field close to the unexposed side of the sheet 68 so that the mixture 134 can be attracted onto the sheet 68 to print the latent image. It will be appreciated that when the trailing edge of the sheet 68 has passed the switch 152 it is no longer necessary to attract the mixture 134 upwardly. Consequently, when the trailing edge of the sheet 68 moves away from the switch 152, the rotary solenoid 150 is de-energized and the magnets 144 will rotate about the longitudinal axis of the frame 146, from the vertical position to a horizontal position, thereby removing the magnetic field from the proximity of the tray 132 and the mixture 134.

When the leading edge of the sheet 68 actuated the switch 154, it also turned on a heater 156 (Fig. 5) of a heater and blower mechanism 157 for fusing the toner onto the sheet 68. After the trailing edge of the sheet 68 has left the switch 154 and a subsequent microswitch 158, the heater 156 is turned off. The finished electrophotographically developed sheet 68 is then discharged onto the exit plate 124.

Referring again to Fig. 1 there is shown a shutter 160 that is normally open for viewing purposes. The shutter 160 may be closed by actuating a shutter solenoid 162 when the print switch 52 (Fig. 5) is closed. Also, as shown in Fig. '5, the switch 128, when actuated, causes the shutter 160 to open by means of a timer solenoid 164 until the timer 129 is automatically turned oif.

Referring-now to Fig. 5, there is shown the electrical system 'oftlie' viewer and reproducer-apparatus 10. The apparatus 1 0 maybe operated from a power source of conventional alternating current (A.-C.) voltage, such as 115 volts A.-C., as available from terminals and 172. The terminal 172 may be grounded. The exposure lamp 24 and a'blowjer motor 174 are connected across the power source through a power on-off switch 176. A normally closed emergency stop switch 178 may be inserted in the ungrounded side of the power source. The shade motor 58a and the mirror'motor 48a are connected across the power source through the viewing switch 50. The shade motor 58b and mirror motor 48b are connected across the power source through the print 'switch 52. The upper limit switches 60 and 46 are connected in series with the motors 58a and 48a, respectively; and the lower limit switches 62 and 42 are connected in series with the motors 58b and 48b, respectively. The lowerlimit switch 62 also serves to connect the power source to the timer 129 when the switch 62 is actuated. The shutter solenoid 162 is also connected across the power source through the print switch 52 and a normally closed switch 180. The switch 180 is mechanically linked to the timer solenoid 164 in a manner whereby 'it is opened when the timer solenoid 16,4 is energized. The clutch-solenoid 80 and the shear solenoid 86 are connected to the power source through the serially connected switches 82 and 62. A high voltage power-supply 181 for the electrostatic charging deplurality of permanent magnets 144 similarly oriented withina rectangular frame I V I tion around its longitudinal axis by means of pivots 148.

146 that is pivoted for .rota- 'vices 88 an'd the motors 76 and 138 are connected to the powersource through,the switches 62 and 128.

The timer solenoid 164 is connected in series with the timer 129 and the switches 128 and 62. The timer 129' may be preset for any given exposure time. After the preset time has expired, the timer 129 will actuates a ormally openswitch 182 to energize the motors 76 and. 138. r r

The rotary solenoid 150 is connected in series with the switches 154, 152, and the switch 62. The heater 156, in the heater-blower mechanism 157, is connected in series with switches '15s and 2. The switch 154a connected 7 in parallel with the switch 158. It will be understood that V the switches 82, 128, 152, 154, and 158 are switches of the type that have an actuating portion projecting in the predetermined path of the moving sheet 68 so that they may be actuated by the moving sheet 68.

The operation of the viewer and reproducer apparatus 10, in accordance with the present invention, will now be explained. The lamp 24 and the blower motor 174 are energized by closing the on-off switch 176. To view the film 21, the viewing switch 58 is closed. The shade 56 is now raised by the motor 58 until the limit switch 60 is actuated. At the same time the movable mirror 38 is raised by the motor 48a until the cam 42 opens the limit switch 46. The film 21 may now be viewed on the frosted screen 34 and focused thereon. 1 U

To'make an electrophotographic print of the image viewed. on the screen 34', the print switch 52 is closed. This action causes the motor 58b to lower the shade 56 until the lower limit switch 62 is actuated. The switch 62 will disconnect the motor 58b from the power source and supply electrical energy to the motors 76 and 138. The charging devices 88 will also be energized from the high voltage power supply 181. The sheet 68 will now be pulled through the charging devices 88 so that the photoconductive layer on the sheet 68 is uniformly electrostatically charged.

The sheet 68 will be pulled between the belts 64 and 90 until the leading edge of the moving sheet 68 actuates the switch 82. The clutch solenoid 80 will now be actuated so that the feed rollers 74 will cease to pull additional sheet material. The shear solenoid 86 will also be actuated by the switch 82, and the sheet 68 will be cut and separated from the roll 66. The sheet 68 will advance until its leading edge actuates the switch 128. The motors 76 and 138 will now be disconnected and the timer 129, preset to a predetermined exposure time, will now be actuated. Such actuation causes the timer solenoid 164 to open the normally closed switch 180 and permits the shutter 160 to open. Light from the lamp 24 will now expose the sheet 68 for a predetermined time in order to produce a latent charge image of the film 21 on the photoconductive surface of the sheet 68. After the preset time of exposure, the timer 129 will cause the normally open switch 182 to close, the timer solenoid 164 will become de-energized, the normally closed switch 180 will now close and the shutter solenoid 162 will cause the shutter 160 to close.

The motors 76 and 138 will be energized again, through the switch 182, and the sheet 68 will proceed along its predetermined path through the rear guides 120 and 122, and thence between the belts 64 and 110. When the leading edge of the sheet 68 actuates both of the switches 152 and 154, the normally horizontally disposed magnets 144 will be rotated 90 to a vertical position by means of the rotary solenoid 150. This will cause the mixture 134 of magnetic carrier and toner to be attracted to the charged surface of the sheet 68. It is also noted that the closing of the switch 154 will cause the heater coil 156, within the heater-blower mechanism 157, to heat up. Thus, when the trailing edge of the sheet 68 leaves the switch 152 the rotary solenoid 150 is de-energized, the magnets 144 will again assume a horizontally disposed position.

When the sheet 68 passes over the heater 156, the toner that has adhered to the latent charged image is fused to the sheet 68. When the trailing edge of the sheet 68 leaves the switch 158, the heater 156 is shut off and the sheet 68 is discharged onto the exit plate 124 as a finished electrophotographic reproduction.

Referring to Fig. 3, there are shown alternative means to the rotary solenoid 150 for rotating the magnets 144 through an angle of 90. A solenoid 150a is connected to. one end of a lever arm 184. The other end of the lever arm 184 is fixed to one of the pivots 148. It will now be understood that actuating the solenoid 150a will cause the rectangular frame 146, containing the magnets '6 144, to be rotated through an angle of 90, from a normally horizontal position to a vertical position.

What is claimed is:

1. In apparatus of the type wherein a sheet of photoconductive material has been uniformly electrically charged and exposed to a light image to provide a charge pattern on saidsheet, means to develop said charge pattern comprising a source for a developer mixture, said mixture comprising a toner powder and magnetic particles, magnetic field producing means spaced apart from said source, means to move said sheet along a predetermined path between said source and said magnetic field producing means with its exposed surface exposed to said mixture in spaced relationship thereto, means actuated by the leading edge of said moving sheet to intensify said magnetic field in the region between said source and said charge pattern on said sheet to cause said mixture to contact said charge pattern and to develop said charge pattern, said last-mentioned means being actuated by the trailing edge of said moving sheet to diminish said magnetic field, heat producing means disposed along said path of movement of said sheet, and switching means actuated by the movement of said sheet to turn said heat on before said sheet passes said heat producing means and to turn said heat off after said sheet has passed said heat producing means.

2. In apparatus of the type for developing an electrostatic latent image on a sheet of material, a source for a mixture of toner and magnetic particles, means to develop a magnetic field adjacent said source, means to move said sheet over said source with said image adjacent thereto and between said source and said magnetic field developing means, means in the path of movement of said sheet including a switch connected to said magnetic field developing means and actuated by the movement of said sheet for producing a strong magnetic field adjacent said sheet whereby to attract said mixture to said latent image to develop said latent image, said last-mentioned means comprising means to diminish said magnetic field when said sheet has moved away from said source.

3. Apparatus for developing a latent electrostatic image on a record receiving member through the use of a developer mix including carrier particles of magnetic material intermixed with electroscopic developer powder, said apparatus comprising a source for said developer mix, magnetic field producing means for attracting said developer mix, means for supporting said magnetic field producing means for movement from an inoperative position to an operative position, means for moving said record receiving member along a path between said source and said magnetic field producing means, and means for moving said magnetic field producing means into said operative positionto bring said developer mix into contact with said record receiving member.

4. Apparatus for developing an electrostatic image on one surface of a sheet with a finely divided toner; said apparatus comprising: a source for a mixture comprising said toner and magnetic carrier particles; magnetic field producing means spaced apart from said source; means for moving said sheet between said source and said magnetic field producing means; and means actuated by said moving sheet to intensify said magnetic field in the region between said source and said image on said sheet to attract said mixture to said sheet to develop said electrostatic image, said last named means being actuated to diminish said magnetic field in said region when said electrostatic image has been developed.

5. Apparatus for developing an electrostatic image on one surface of a sheet with a finely-divided toner; said I apparatus comprising: a source for a mixture comprising said toner and magnetic carrier particles; magnetic field producing means spaced apart from said source; means for moving said sheet between said magnetic field producing means and said source with said one surface exassoes posed to said source; means associated with said magnetic field producing means and actuated by the leading edge of said sheet to initiate attraction of said mixture toward said one surface and actuated by the trailing edge of said sheet to terminate said attraction.

6. Apparatus for developing an electrostatic image on a sheet of material, said apparatus comprising: a source for a mixture of toner and magnetic particles, a plurality of similarly oriented magnets secured in a frame adjacent said source, means for moving said sheet along a path of travel between said source and said frame, means for rotating said frame from a first position wherein the poles of said magnets are aligned in parallel relation with respect to said path to a second position wherein said poles are aligned normal to said path, switching means for controlling rotation of said frame, said switching means being disposed along said path and actuated 8 by movement of said :paper thereover to cause said frame to be maintained in said second position only while said sheet is between said source and said frame, said mixture being attracted to said electrostatic image and toner caused to adhere thereto while said frame is in said second position.

References 'Cited in the file of this patent UNITED STATES PATENTS 2,047,221 Pechy July 14, 1936 2,221,776 Carlson Nov. 19, 1940 2,329,392 Crane Sept. 14, 1943 2,786,440 Giaimo Mar. 26, 1957 2,791,949 Simmons et al. May 14, 1957 2,846,333 Wilson Aug. 5, 1958 2,854,947 Giaimo Oct. 7, 1958 

